Cold-weather birds flock to Florida - but why?

Razorbills, cold-weather birds with penguin-like features, have been unlikely visitors to South Florida over the past few weeks, attracting bird watchers to the coast of Palm Beach County and creating speculation about why they’re here.

“This is a historic ornithological event,” said Carl Edwards, an avid bird-watcher from West Palm Beach who took three boat trips out of the Boynton Inlet recently to observe the Northeastern, ocean-going birds, which have also been spotted off Miami Beach and the Florida Keys.

Edwards estimates he saw 900 razorbills during two trips out of the inlet on Dec. 14. Almost all of the birds were headed south, he said, most likely in search of food.

Black with white undersides, razorbills weigh about 1.6 pounds, measure about 17 inches in length and have a wingspan of about 26 inches, according to the National Audubon Society.

Razorbills can dive several hundred feet below the ocean’s surface to find food, and can walk upright, like penguins, on land. Their diet consists of small, cold-water fish of the northern Atlantic, including juvenile cod, sand lance and capelin.

Their predators include Arctic foxes and polar bears.

Razorbills have been spotted 14 times in Florida in the past, but only single or a few birds were reported in previous sightings, said Marshall Iliff, a bird expert with the Cornell Lab of Ornithology and lead author of a recent article about the Florida razorbill invasion on the website eBird.org.

Recent razorbill sightings off the South Florida coast have included flocks of more than 20, Iliff said.

Why they are here is open to debate.

Andy Kratter, an ornithologist with the Florida Museum of Natural History in Gainesville, said beach erosion and other disturbances brought by Hurricane Sandy to the coasts of New York and New Jersey probably prompted the razorbills to fly south.

However, Iliff of the Cornell Lab of Ornithology said he believes above-average sea-surface temperatures in the Northeast are responsible.

Iliff said the reason for the rise in sea-surface temperature is unclear, but he noted on eBird that it could be related to cycles of ocean warming and cooling or long-term climate change.

The first razorbills documented off the coast of Palm Beach County were spotted Dec. 9 from the north jetty at the Boynton Inlet, said Linda Humphries of the Audubon Society of the Everglades.

“I’m really excited that they’re here,” Humphries said. “People have been coming from all over Florida to see them.”

After razorbills were seen off Miami Beach and the Keys, bird-watchers tracked them as they continued their journey north along Gulf Coast toward the Florida Panhandle.

Although the unprecedented migration has been exciting for bird-watchers, it has been tough on some of the birds, several of which have washed up dead on Florida beaches.

The Busch Wildlife Sanctuary, which operates a wildlife hospital in Jupiter, took in another type of Northeastern sea bird called a dovekie last weekend that apparently was too weak to feed and had washed ashore.

Malnourished sea birds tend to bob around on the ocean and eventually wash ashore, said David Hitzig, executive director of the wildlife sanctuary, which helps them regain strength before releasing them back into the wild.

But Hitzig said the birds’ prognosis generally is not good.

“Once they wash up on shore, you’re looking at the tail end of their story,” Hitzig said.